Check strap assembly



Nov. 29, 1966 c. R. MESSER CHECK STRAP ASSEMBLY Filed Oct. 9, 1964 FIG. 3'

INVENTOR.

CHESTER R. MESSER United States Patent 3,288,174 CHECK STRAP ASSEMBLY Chester R. Messer, Concord, N.H., assignor to Page Belting Company, Concord, N.H., a corporation of New Hampshire Filed Oct. 9, 1964, Ser. No. 402.737 2 Claims. (Cl. 1 3916l) This invention comprises a new and improved check strap assembly for controlling the stroke of the picker stick in fiy shuttle looms.

Many check strap devices employ, at least as one component, an endless loop of woven fabric which is engaged on opposite sides of the loop by a set of friction fingers that retard the bodily longitudinal movement of the loop and the enclosed picker stick. While these friction fingers are usually adjustable it often happens that their retarding effect becomes unbalanced, that is to say, one set of friction fingers will develop a more powerful drag on its side of the loop than the other. The result is that one side of the loop takes an unequally large share of the burden and so tends to wear rapidly.

I have discovered that a very substantial improvement in the life of the check assembly and in the character of its action is achieved by impregnating or coating the woven textile band of the loop with a thermosetting hardening and smoothing compound, such for example as polyurethane. The effect of this impregnant is somewhat to stiffen and smooth the textile band in making its retarded passage between the friction fingers, to prevent any tendency to kink or snub and to strengthen the band, particularly at its upper edge where it is subjected to maximum beating of the picker stick.

Another undesirable result of unbalanced friction con ditions is that the loop tends to creep or progress in one direction or the other thus introducing an uneven response to the action of the whole device in continued operation.

I have discovered that this condition may be remedied to a great extent by providing index marks on or near an end of the loop which marks may be located opposite to each other or in predetermined relation to some fixed gague. When the index marks are initially registered exactly opposite to each other on the sides of the loop any tendency of the loop to creep is at once visually brought to the notice of the loom fixer and the necessity for correction of the friction fingers is indicated to be in order.

The loop is impregnanted preferably in those areas that are subjected to the engagement with the friction fingers, leaving unstiffened areas where the loop naturally hinges under the impact of the picker stick. By adding color to the impregnant the treated areas may be utilized also to define such index marks.

These and other features of the invention will be best understood and appreciated from the following description of a preferred embodiment thereof, selected for pur poses of illustration and shown in the accompanying drawings in Which FIG. 1 is a plan view of the loop with the picker stick and friction fingers shown in section,

FIG. 2 is a view in longitudinal section on the line 2-2 of FIG. 1,

FIG. 3 is a view in perspective of the textile band of the loop, and

FIG. 4 is a fragmentary view of a loop having impregnated areas of modified shape.

As herein shown the assembly includes a single-ply endless loop 11 within which oscillates the picker stick 10. The loop is engaged at opposite sides by friction fingers 20-21 and these are mounted adjustably in the loom frame to regulate and control the frictional drag 3,288,174 Patented Nov. 29, 1966 on the loop as it is bodily shifted back and forth by the action of the picker stick. In many looms the loop 11 is employed in combination with an outer supplementary strap such as that shown in United States Patent 2,796,086 June 18, 1957. It is contemplated that the endless loop of the present invention may be used with or without such outer strap. The loop 11 is formed of heavy webbing such as canvas or nylon or combinations thereof and is made endless by a beveled cemented splice as indicated in FIG. 3. While the endless loop 11 must be flexible enough to conform to the action of the picker stick excess flexing has often heretofore tended to cause snubbing or kinking of the loop in its areas of engagement by the friction fingers. This objection is obviated in accordance with the present invention by impregnating the textile loop 11 in those areas 12 which come within range of the friction fingers with polyurethane or equivalent composition. The effect of this impregnation is to stiffen the sides of the loop and smooth its surfaces so that it is maintained substantially flat and travels without substantial undulation between the friction fingers. The impregnated area 12 as Well defined in FIG. 3 preferably includes the splice in the side of the loop.

In FIGS. 2 and 3 the impregnated areas 12 in the sides of the loop 11 are shown as tapering at both ends while separate impregnated areas 13 are indicated at both ends of the strap in FIG. 4 and are applied to impart additional strength to the loop at the point where it suffers maximum deflection from the picker stick. This tapered shape has advantages because it avoids cleavage straight across the strap and distributes the hinge action thus increasing its life.

Index marks 15 are herein shown as symmetrically applied to the upper edge of the loop 11 where they are to be readily seen. These are originally located in precisely opposite positions in the loop and their relative displacement gives visible Warning in the event that an objectionable creeping of the composite loop should take place as a result of unbalanced setting of the friction fingers.

The impregnant employed in treating the areas 12 of the loop is preferably pigmented to contrast in color against the background of the body of the loop. The impregnated areas are thus sharply defined by the rounded and converging boundary lines 16 at both ends. These lines lie in substantially parallel opposite relation and themselves serve as index marks that indicate by relative displacement if any creeping of the loop is taking place.

In FIG. 4 the loop 11 is shown as having impregnated side areas 12' and end areas 13 defined by square end boundary lines. The treated areas 13 strengthen the loop to withstand direct impact of the picker stick while leaving the loop free to flex in its untreated areas.

The areas 12 are substantially strengthened, hardened and smoothed by impregnation with a thermosetting polyurethane or phenol formaldehyde, or by PVC or other suitable compound of synthetic resin. The areas to be treated by be set off by profile clamping plates or templets and the loop immersed in a hot solution of the compound until saturated.

In the figures of the drawing the treated areas are lined to indicated color contrast, for example dark blue areas with pointed, rounded or square ends, against a cream colored background of the fabric.

Having thus disclosed by invention and described in detail an illustrative embodiment thereof, I claim as new and desire to secure by Letters Patent:

1. In a picker stick check assembly, an endless woven fabric loop movable between friction fingers which engage it at both its opposite sides and being impregnated with a plastic hardening and smoothing compound in its side areas within range of its movement between the said friction fingers, said impregnated areas being visible and 2,698,032 12/ 1954 Bacon 139-161 Well defined by color contrast with the body of the loop 2,741,273 4/1956 Robert 139161 and having converging ends effective in distributing work- 2,822,828 2/ 1958 Crocker 139-161 ing stresses across the width of the loop. 3,067,484 12/ 1962 Rasero et al. 139161 2. In a check strap assembly, an endless loop as de- 5 3,114,397 12/1963 Messer 139161 scribed in claim 1, further characterized in that the two 3,228,429 1/ 1966 Messer 139161 sides of the loop are provided with gauge marks initially registering at opposite sides of the loop and indicating F REI N PATENTS by their relative positions the occurrence of any creeping 542 412 6 19 57 Canada of the p in operation 10 1,376,347 9/1964 France.

4,224 2156G B't'. References Cited by the Examiner 7 5 9 feat H mm UNITED STATES PATENTS MERVIN STEIN, Primary Examiner.

2,371,025 3/ 1945 Carter 139-161 J. KEE CHI, Assistant Examiner.

2,533,646 12/1950 Wakefield "139-161 

1. IN A PICKER STRICK CHECK ASSEMBLY, AN ENDLESS WOVEN FABRIC LOOP MOVABLE BETWEEN FRICTION FINGERS WHICH ENGAGE IT AT BOTH ITS OPPOSITE SIDES AND BEING IMPREGNATED WITH A PLASTIC HARDENING AND SMOOTHING COMPOUND IN ITS SIDE AREAS WITHIN RANGE OF ITS MOVEMENT BETWEEN THE SAID FRICTION FINGERS, SAID IMPREGNATED AREAS BEING VISIBLE AND AND HAVING CONVERGING ENDS EFFECTIVE IN DISTRIBUTING WORKING STRESSES ACROSS THE WIDTH OF THE LOOP. 